Conventional disk drives for magnetic recording purposes utilize a magnetic recording disk unit including a disk of flexible material rotatably carried in a jacket of a relatively stiff material, such as stiff plastic or the like. A leading disk unit which has been commercially available for a number of years is formed by sandwiching a generally square, rigid plastic member between a pair of stiff plastic sheets with the plastic member having a circular opening therethrough in which the magnetic disk is rotatably disposed. Thus, the plastic member retains the disk between the sheets and substantially rigidifies the jacket portion surrounding the disk which is unnecessary and increases production costs.
Other types of jackets for magnetic disks are of similar complexity. They, therefore, suffer the same drawbacks as the jacket described above.
A need has, therefore, arisen for a jacket for a magnetic disk which is simpler in construction than that of conventional types yet the disk is adequately protected at all times within the jacket and the jacket itself can have a write enable function in the same manner as those of conventional disk units.